US 7785155 B2
An electronic device having one or more contact posts is disclosed having a sleeve slidably mounted around the contact post and lockable by a push-push latching system in a retracted position in which the sleeve is below an upper end of the contact post and an extended position in which the sleeve extends around and covers the upper end of the contact post. The sleeve and contact post may have respective apertures extending transversely therethrough, which are aligned when the sleeve is slightly retracted to receive a probe. Alternatively, an ECG electrode clip may engage an end of the contact post when it is exposed by the sleeve being in the retracted position.
1. A method for preventing accidental electric shock comprising:
moving an insulating sleeve from an extended position in which the sleeve extends around and covers a contact post to a retracted position in which an end of the contact post is exposed;
latching the insulating sleeve in the retracted position;
attaching an electrode lead to the exposed end of the contact post while the insulating sleeve is in the retracted position;
subsequently removing the electrode lead from the contact post; and
after removing the electrode lead from the contact post, returning the sleeve to its extended position.
2. The method of
moving the sleeve toward the retracted position so that the aperture of the sleeve is aligned with the aperture of the contact post; and
inserting a probe through the aligned apertures.
3. The method of
4. The method of
5. The method of
6. The method of
pushing downwardly on the sleeve against the resilient bias to urge a plurality of discrete urging members secured to the sleeve circumferentially spaced apart from one another such that at least one of the discrete urging members presses against at least one sloped upper surface secured to a ratchet slidably mounted relative to the housing thereby causing the ratchet to slide downwardly against a biasing member and out of engagement with at least one vertical guide constraining rotation of the ratchet, the ratchet rotating in a first direction upon coming out of engagement with the vertical guides under the force of the at least one of the urging members on the sloped upper surface; and
releasing the discrete urging members such that the resilient bias urges the ratchet upwardly against a stop positioned adjacent the vertical guide.
7. The method of
the sleeve further includes an engagement member secured to the sleeve and extending outwardly therefrom; and
the act of moving the sleeve from an extended position in which the sleeve extends around and covers a contact post to a retracted position from the extended position to the retracted position comprises moving the sleeve by pressing the engagement member;
the at least one sloped upper surface includes a plurality of sloped upper surfaces;
the sleeve moves between the extended and protracted positions along a longitudinal axis; and
wherein the discrete urging members are disposed such that none of the discrete urging members engage the sloped upper surface of the plurality of sloped upper surfaces having a portion thereof located angularly about 90 degrees in the first direction about the longitudinal axis from an angular position of the engagement member.
8. The method of
again downwardly urging the plurality of discrete urging members such that at least one of the discrete urging members presses against the at least one sloped upper surface such that the ratchet rotates out of engagement with the stop and into engagement with a second vertical guide adjacent the stop; and
again releasing the discrete urging members such that the biasing member urges the ratchet upwardly within the vertical guide thereby urging the discrete urging members and sleeve to move upwardly.
9. A method for preventing accidental electric shock comprising:
moving an insulating sleeve comprising a transverse aperture formed in a wall thereof from an extended position in which the sleeve extends around and covers a contact post to a retracted position in which the transverse aperture of the insulative sleeve is aligned with a transverse aperture extending through the contact post;
inserting a probe through the aligned apertures of the sleeve and the contact post;
subsequently removing the probe from the contact post; and
after removing the probe from the contact post, returning the sleeve to its extended position.
10. The method of
11. The method of
This application is a divisional application of U.S. patent application Ser. No. 11/853,713, filed Sep. 11, 2007.
The entire disclosure of the prior application, from which a copy of the oath or declaration is supplied, is considered to be part of the disclosure of the instant application and is hereby incorporated by reference therein.
This invention relates to electrical testing equipment, and, more particularly to an apparatus and method for preventing accidental electric shock in testing equipment having exposed contact posts.
Medical equipment must be carefully tested and calibrated in order to ensure that it will function properly in critical situations. Electrocardiogram (ECG) testers are an example of such test equipment. As shown in
Hospital equipment, including ECG monitors, must be tested to ensure that they do not pose a shock hazard resulting from short circuits to an AC line power lead. The ECG leads, as well as cases of ECG monitors, are normally isolated from AC line voltage by suitable insulation, which can become damaged. ECG testers check electrical isolation of ECG monitors by applying line voltage to the contact posts 12. The exposed contact posts 12 in prior art systems can be hazardous inasmuch as they can be inadvertently touched and cause electrocution. Accordingly, it would be an advancement in the art to provide a conveniently used apparatus and method for shielding the contact posts of ECG testers and like equipment when they are not covered by an electrode clip.
In one aspect of the invention, an electronic device, such as an ECG tester, includes a contact post having first and second ends mounted on a housing having the first end exposed and the second end electrically coupled to a circuit board operable to apply signals to and receive signals from the contact post. An insulative sleeve is slidably mounted on the contact post and engages a latching mechanism that secures the sleeve in either of two positions, an extended position in which the sleeve is positioned over the contact post in order to protect and insulate the post and a retracted position in which the first end of the contact post is exposed.
In another aspect of the invention the latching mechanism is a push-push latch. An engagement member may be secured to the sleeve to enable a user to push the sleeve into the retracted and extended positions.
In another aspect of the invention, the sleeve has an aperture extending transversely through a wall thereof such that a clip, such as a banana plug, may engage the first end of the contact post when the sleeve is in the extended position.
In some embodiments, the shield 18 includes an aperture 26 that extends through a wall of the shield 18. When the shield 18 is retracted slightly, but not enough to expose the upper end 22 of the contact post 20, the aperture 26 is aligned with an aperture 27 formed in the contact post 20. As shown in
An engagement member 32 may be secured to the sleeve 30 and provide an area for a user to safely press to move the sleeve 30 into the extended and retracted positions of
The indexing members 40 engage arms 44 formed on a ratchet 46. The arms 44 include sloped surfaces 48, such that pressing the indexing members 40 against the arms 44 causes the ratchet to rotate in direction 50 (
Although the present invention has been described with reference to the disclosed embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. Such modifications are well within the skill of those ordinarily skilled in the art. Accordingly, the invention is not limited except as by the appended claims.